Recently, communication technology, and particularly wireless communication technology are developed. By using the wireless communication technology, codeless communication between an electronic device and a terminal can be established, whereby connecting between the electronic device and the terminal is simplified, and the location of the electronic device or the terminal is not limited. Therefore, the wireless communication technology becomes higher in convenience than wire communication technology.
For example, as wireless communication technology applicable to an electronic device, Bluetooth (registered trademark) has been known. By using the wireless communication technology of this Bluetooth, audio data can be transferred from a portable terminal such as a mobile telephone device or from a portable music player without using an audio cable to a terminal device such as a headset.
As transmission profiles of audio data, for example, “Advanced Audio Distribution Profile (A2DP)” (Advanced Audio/Video Distribution Profile (Bluetooth SIG)) and “Generic Advanced Audio/Video Distribution Profile” (Generic Advanced Audio/Video Distribution Profile (Blue-tooth SIG)) have been known. These are standards for performing streaming transfer of audio data between Bluetooth-connected devices in real time.
For example, in a portable information terminal such as a mobile telephone device or in a portable music player, audio data is compressed by a format of SBC (Sub Band Coding), MP3 (MPEG1 Audio Layer-3), or ATRAC (Advanced Transform Acoustic Coding) 3 and transferred by packet unit. On the other hand, in a terminal device such as a speaker or a headset, without waiting reception of all the packets, simultaneously with reception of data, its data is reproduced. Hereby, a user can listen to sound from the portable information terminal or the portable music player in substantially real time through the terminal device such as the speaker or the headset.
Further, the following technology is also proposed: in case that incoming sound call interrupts transmission of audio data to the terminal device such as a headset, the transmission of the audio data to the terminal device is stopped and audio data regarding the incoming sound is transmitted to the terminal device (refer to, for example JP-A-2006-319572).